Arrangement of multiple valves for an internal combustion engine

A multiple-valve internal combustion engine having three intake valves and two exhaust valves provided for a common cylinder, characterized in that the three intake valves and the two exhaust valves are disposed in a cylinder head thereof with the intake valves positioned on one side on a circumference surrounding a center line of a combustion chamber thereof and the exhaust valves positioned on the other side thereon in a radial disposition wherein longitudinal axes all valves cross one another at a point on a longitudinal axis of the cylinder, and an ignition plug is provided in a space between the two exhaust valves and is inserted through the cylinder head in an inclined posture with a forward end thereof directed toward the center of the combustion chamber, and a single common cam shaft is provided horizontally at an intermediate position of the cylinder head between a disposition section of the intake valves and a disposition section of the exhaust valves so that the respective valves may be driven by the common shaft.